Positron Emission Transaxial Tomography (PETT) has as its major virtue (aside from the ability to obtain tomographic images) the ability to allow the quantitation of the amount of a tracer labeled with a positron emitter in a volume element of tissue of a size related to the resolution of the instrument. In addition, the time course of the tracer in vivo can be measured, and therefore, the dynamics of biochemical and physiological processes can be measured (appropriate models being available). We propose to continue to conduct basic research on the preparation of the required positron emitters specifically those that are identical with the constituents of the "molecule of life" i.e. carbon (carbon-11), nitrogen (nitorgen-13), and oxygen (oxygen-15) and also the useful radionuclide, fluorine-18. This research will focus on development of new methodology involving targetry and precursor production utilizing a new generation of small so called "medical cyclotrons", an example of which is the JSW-168 to be installed at BNL in early 1982. Secondly new syntheses and synthetic methods for the rapid incorporation of these nuclides into radiotracers to be used primarily in neuroscience will be developed. New synthetic methods for introducing fluorine-18 into organic molecules will be developed along with new syntheses of labeled sugars for studying glucose metabolism, neuroleptics for in vivo receptor studies and compounds for probing specific enzyme activity. Where possible the "prodrug" approach will be used when compounds show unsatisfactory uptake in the target site. Thirdly, testing methods both in vitro and in vivo will be developed specifically focussed on tracers labeled with positron emitters especially in the carrier free or near carrier free state. Finally, technology transfer will be developed and facilitated, building on the efforts in this area begun at BNL in past years. A formal training course will also be developed in recognition of the great increase in informal training carried out at BNL in the past several years in the area of accelerator use, synthesis and evaluation of compounds labeled with positron emitters and application to problems of human disease.